Effect of light deprivation on GABA metabolism in subcellular fractions of the rabbit visual system

Abstract: Specific activity of glutamate decarboxylase was decreased in subfractions of light and heavy synaptosomes, and gamma-aminobutyric acid (GABA) transaminase activity--also in subfractions of free mitochondria, isolated from visual zone of brain cortex and of anterior mesencephalon but not from locomotive region of brain cortex of the light-deprived rabbits. Decrease in the ratio GABA transaminase/glutamate decarboxylase indicated distinct inhibition of GABA degradation as compared with its synthesis due to absence of sensory impulsation within the early periods of postnatal ontogenesis of the animals